Notching machine



Oct. 24, 1950 G. G. CHRISTENSEN NOTCHING MACHINE Filed Aug. 15, 1947 INVENTOR. Giff/Flaw 6. ['m/sri/wn/ Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE This invention relates to a notching machine and more particularly to a machine for notching the corners of sheet metal blanks such as are used for conduits in air heating systems and the like.

An object of this invention is to provide a machine which will cut a notch in the corner portion of a blank and which is particularly suited for cutting such corners in blanks of elbows and the like, as well as for blanks of straight conduits.

Further objects and advantages of this invention will be more clearly understood from the following description and from the accompanying drawings, in which- Fig. 1 is an elevational front view of a notching machine embodying my invention.

Fig. 2 is a plan view in section on line 2-2 of Fig. 1.

Fig. 3 is a View similar to Fig. 2, but showing a modification of the machine.

Fig. 4 is a plan view of a sheet metal blank for an elbow showing the notches formed by my improved machine.

Fig. 5 is a similar view showing a straight blank.

As shown in the drawings, my notching machine comprises a base 5 having a plurality of guide posts B6 thereon upon which is slidably mounted a punch plate I having attached sleeve bearings which is operated by means of a lever 8 that is pivoted on a post 9 and operates the said plate by a link 9--a.

A die I is mounted on the base 5. This die is flat in form and has a notch therein with cutting edges I I-l l which are relatively disposed to cut a notch in a blank of sheet metal with the edges of said notch relatively disposed at a desired angle.

The said die carries thereon a positioning bar l2 which is slidably secured upon the top surface of the die plate I!) and extends therefrom beyond the extremity of the said die plate. A supporting plate I3 is carried by said bar l2 in order to support a sheet metal blank in said machine.

The said die plate also carries a separate positioning bar M which extends at right angles to the bar l2, and which is also slidably mounted upon the surface of the die plate, as shown, preferably by means of a clamping screw l and guide slots l6--l6 which retain the said bar in accurate relation to the cutting edges of the die.

A punch I! is carried by the plate I and has cutting edges thereon in register with the cutting edges ll-|l of the die.

.As shown in Fig. 4;. a blank l8. for an elbow conduit, is notched at l9-'|9 to permit the proper bending of the blank in con'structinga conduit. In Fig. 5 there is shown a sheet of metal in the form of a blank which is used for the sides of a' straight conduit, and has the notches 2;I-2l.

In order to permit cutting of the notches I9I-9 in the corners of ablank for an elbow, such as 18, I provide a stop member 22 having a positioning point 23 which engages the curved edge 24 of the elbow blank to retain it inposition under the punch I! for cutting the notches l9--l9. The said point 23, being close to the punch 11, permits its engagement with the edge of the blank close to the notch so that the curvature of said edge will not make a material difierence in accurately positioning said blank for cuttingthe notches of the proper size. When it is desired to cut the said notches, the blank, indicated in dotted lines, is first placed against the positioning bar 12 and against the end of said point 23, thus bringing the corner portion of the blank in proper position under the punch I! for cutting one of the notches IS. The blank may then be turned over so that the point 23 will engage the opposite edge and thereby permit positioning of the blank for cutting the opposite notch.

In cutting the notches in a straight blank such as 20, the positioning bars 12 and I4 may be arranged as illustrated in Fig. 3. The blank is then placed against the said bars, as shown in dotted lines, and the machine operated for cutting oil the corner portions.

The surface of the die plate may be graduated, as at 25-26, to facilitate proper adjustment of the positioning bars for the different sizes of the notches which may be cut on said machine.

By providing the elongated positioning bars l2 and M which extend beyond the extremities of the die plate, I am able to reduce materially the size of said machine and still permit the cutting of notches in large blanks since the said blanks may be supported on the supporting plates 13 and I4-a as shown.

I claim:

1. A notching machine of the character described comprising a base, a die plate mounted on said base, a positioning baradjustably carried on said die plate and projecting therefrom, a supporting plate carried by the projecting portion of said positioning bar for supporting a workpiece in position on said die plate, the said die plate having a corner portion thereof notched and provided with cutting edges, a punch plate slidably carried on said base, a punch on said punch plate, and means tor operating sa d punch 299mm tion with the cutting edges on the die plate for cutting notches in said work piece.

2. A notching machine of the character described comprising a base, a die plate mounted on said base, positioning bars slidably mounted and adjustable on the surface of said die plate, the said positioning bars projecting from the die plate, a supporting plate secured to each of said positioning bars exteriorly of the die plate and having the upper surface thereof coplanar with the surface of the die plate, cutting edges in said die plate, a punch cooperating with said cutting edges and carried on said base, and means for operating said punch.

3. A notching machine of the character described comprising a base, a die plate secured to said base, a notching portion having cutting edges in said die plate, a positioning bar adjustably slidable upon the surface of said plate and projecting therefrom, a supporting plate secured to said positioning bar exteriorly of said die plate and being movable therewith the upper surface of said plate being on a plane with the surface of said die plate, a punch movable relatively to said cutting edges, and means for operating said punch.

4. A notching machine of the character described comprising a base, a die plate carried on said base, a notching portion in said plate having cutting edges, a positioning bar extending from 4 said die plate, a supporting plate secured to said positioning bar exteriorly of the die plate having its upper surface on a plane with the plane of said die plate, and a guiding member on said die plate slidably adjustable relative to said cutting edges and having a projection adjacent to one side of said notch for positioning a blank relatively to the cutting notch by engagement with an edge portion of said blank close to said cutting notch.

5. A notching machine comprising a die plate having cutting edges, a positioning bar slidable on said die plate and extending therefrom in one REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 236,613 Nelson Jan. 11, 1881 1,359,427 Plummer Nov. 16, 1920 

